---
title: Troubleshooting
description: Fix common issues and optimize Jan's performance with this comprehensive guide.
keywords:
  [
    Jan,
    troubleshooting,
    error fixes,
    performance issues,
    GPU problems,
    installation issues,
    common errors,
    local AI,
    technical support,
  ]
---

import { Tabs } from 'nextra/components'
import { Callout, Steps } from 'nextra/components'

# Troubleshooting

## Getting Help: Error Logs

When Jan isn't working properly, error logs help identify the problem. Here's how to get them:

### Quick Access to Logs

**In Jan Interface:**
1. Look for **System Monitor** in the footer
2. Click **App Log**

![App log](./_assets/trouble-shooting-02.png)

**Via Terminal:**
```bash
# macOS/Linux
tail -n 50 ~/Library/Application\ Support/Jan/data/logs/app.log

# Windows  
type %APPDATA%\Jan\data\logs\app.log
```

<Callout type="warning">
Remove any personal information before sharing logs. We only keep logs for 24 hours.
</Callout>

## Common Issues & Solutions

### Jan Won't Start (Broken Installation)

If Jan gets stuck after installation or won't start properly:

<Tabs items={['macOS', 'Windows', 'Linux']}>
<Tabs.Tab>

**Clean Reinstall Steps:**

1. **Uninstall Jan** from Applications folder

2. **Delete all Jan data:**
```bash
rm -rf ~/Library/Application\ Support/Jan
```

3. **Kill any background processes** (for versions before 0.4.2):
```bash
ps aux | grep nitro
# Find process IDs and kill them:
kill -9 <PID>
```

4. **Download fresh copy** from [jan.ai](/download)

</Tabs.Tab>
<Tabs.Tab>

**Clean Reinstall Steps:**

1. **Uninstall Jan** via Control Panel

2. **Delete application data:**
```cmd
cd C:\Users\%USERNAME%\AppData\Roaming
rmdir /S Jan
```

3. **Kill background processes** (for versions before 0.4.2):
```cmd
# Find nitro processes
tasklist | findstr "nitro"
# Kill them by PID
taskkill /F /PID <PID>
```

4. **Download fresh copy** from [jan.ai](/download)

</Tabs.Tab>
<Tabs.Tab>

**Clean Reinstall Steps:**

1. **Uninstall Jan:**
```bash
# For Debian/Ubuntu
sudo apt-get remove jan

# For AppImage - just delete the file
```

2. **Delete application data:**
```bash
# Default location
rm -rf ~/.config/Jan

# Or custom location
rm -rf $XDG_CONFIG_HOME/Jan
```

3. **Kill background processes** (for versions before 0.4.2):
```bash
ps aux | grep nitro
kill -9 <PID>
```

4. **Download fresh copy** from [jan.ai](/download)

</Tabs.Tab>
</Tabs>

<Callout type="info">
Make sure Jan is completely removed from all user accounts before reinstalling.
</Callout>

### NVIDIA GPU Not Working

If Jan isn't using your NVIDIA graphics card for acceleration:

<Steps>

### Step 1: Check Your Hardware Setup

**Verify GPU Detection:**

*Windows:* Right-click desktop → NVIDIA Control Panel, or check Device Manager → Display Adapters

*Linux:* Run `lspci | grep -i nvidia`

**Install Required Software:**

**NVIDIA Driver (470.63.01 or newer):**
1. Download from [nvidia.com/drivers](https://www.nvidia.com/drivers/)
2. Test: Run `nvidia-smi` in terminal

**CUDA Toolkit (11.7 or newer):**
1. Download from [CUDA Downloads](https://developer.nvidia.com/cuda-downloads)
2. Test: Run `nvcc --version`

**Linux Additional Requirements:**
```bash
# Install required packages
sudo apt update && sudo apt install gcc-11 g++-11 cpp-11

# Set CUDA environment
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64
```

### Step 2: Enable GPU Acceleration in Jan

1. Open **Settings** > **Hardware**
2. Turn on **GPU Acceleration**
3. Check **System Monitor** (footer) to verify GPU is detected

![Hardware](./_assets/trouble-shooting-01.png)

### Step 3: Verify Configuration

1. Go to **Settings** > **Advanced Settings** > **Data Folder**
2. Open `settings.json` file
3. Check these settings:

```json
{
  "run_mode": "gpu",          // Should be "gpu"
  "nvidia_driver": {
    "exist": true,            // Should be true
    "version": "531.18"
  },
  "cuda": {
    "exist": true,            // Should be true
    "version": "12"
  },
  "gpus": [
    {
      "id": "0",
      "vram": "12282"         // Your GPU memory in MB
    }
  ]
}
```

### Step 4: Restart Jan

Close and restart Jan to apply changes.

</Steps>

#### Tested Working Configurations

**Desktop Systems:**
- Windows 11 + RTX 4070Ti + CUDA 12.2 + Driver 531.18
- Ubuntu 22.04 + RTX 4070Ti + CUDA 12.2 + Driver 545

**Virtual Machines:**
- Ubuntu on Proxmox + GTX 1660Ti + CUDA 12.1 + Driver 535

<Callout type="info">
Desktop installations perform better than virtual machines. VMs need proper GPU passthrough setup.
</Callout>

### "Failed to Fetch" or "Something's Amiss" Errors

When models won't respond or show these errors:

**1. Check System Requirements**
- **RAM:** Use models under 80% of available memory
  - 8GB system: Use models under 6GB
  - 16GB system: Use models under 13GB
- **Hardware:** Verify your system meets [minimum requirements](/docs/desktop/troubleshooting#step-1-verify-hardware-and-system-requirements)

**2. Adjust Model Settings**
- Open model settings in the chat sidebar
- Lower the **GPU Layers (ngl)** setting
- Start low and increase gradually

**3. Check Port Conflicts**
If logs show "Bind address failed":

```bash
# Check if ports are in use
# macOS/Linux
netstat -an | grep 1337

# Windows
netstat -ano | find "1337"
```

**Default Jan ports:**
- API Server: `1337`
- Documentation: `3001`

**4. Try Factory Reset**
1. **Settings** > **Advanced Settings**
2. Click **Reset** under "Reset To Factory Settings"

<Callout type="warning">
This deletes all chat history, models, and settings.
</Callout>

**5. Clean Reinstall**
If problems persist, do a complete clean installation (see "Jan Won't Start" section above).

### Permission Denied Errors

If you see permission errors during installation:

```bash
# Fix npm permissions (macOS/Linux)
sudo chown -R $(whoami) ~/.npm

# Windows - run as administrator
```

### OpenAI API Issues ("Unexpected Token")

For OpenAI connection problems:

**1. Verify API Key**
- Get valid key from [OpenAI Platform](https://platform.openai.com/)
- Ensure sufficient credits and permissions

**2. Check Regional Access**
- Some regions have API restrictions
- Try using a VPN from a supported region
- Test network connectivity to OpenAI endpoints

### Performance Issues

**Models Running Slowly:**
- Enable GPU acceleration (see NVIDIA section)
- Use appropriate model size for your hardware
- Close other memory-intensive applications
- Check Task Manager/Activity Monitor for resource usage

**High Memory Usage:**
- Switch to smaller model variants
- Reduce context length in model settings
- Enable model offloading in engine settings

**Frequent Crashes:**
- Update graphics drivers
- Check system temperature
- Reduce GPU layers if using GPU acceleration
- Verify adequate power supply (desktop systems)

## Need More Help?

If these solutions don't work:

**1. Gather Information:**
- Copy your error logs (see top of this page)
- Note your system specifications
- Describe what you were trying to do when the problem occurred

**2. Get Community Support:**
- Join our [Discord](https://discord.com/invite/FTk2MvZwJH)
- Post in the **#🆘|jan-help** channel
- Include your logs and system info

**3. Check Resources:**
- [System requirements](/docs/desktop/troubleshooting#step-1-verify-hardware-and-system-requirements)
- [Model compatibility guides](/docs/desktop/manage-models)
- [Hardware setup guides](/docs/desktop/)

<Callout type="info">
When sharing logs, remove personal information first. We only keep logs for 24 hours, so report issues promptly.
</Callout>
